----- Original Message ----- > From: "Scott Helms" <khe...@ispalliance.net>
> > Let us be clear: if you're getting "digital telephone" service from a > > cable television provider, it is *not* "VoIP", in the usage in which > > most speakers mean that term -- "Voice Over Internet" is what they > > should be saying, and cable-phone isn't that; the voice traffic rides over > > a separate DOCSiS channel, protected from both the Internet and CATV > > traffic on the link. > > No, this incorrect. Packet Cable most certainly _is_ VOIP (a MGCP > variant to be precise until 2.0 after which it is SIP). While a few > providers, usually for non-technical reasons, did deploy an entirely > separate set of downstream and upstream interfaces that is far from the > norm. AFAIK the only top 20 MSO to do so in scale was Charter and I > don't know if they continue that today. Comcast, the largest cable > telephone provider certainly does not nor do providers need to since > any Packetcable CMTS and EMTA combo offers reliable prioritization in the > same channel(s) as the normal data path. Indeed. Then either Bright House is lying, their deployment was pretty early, or I'm nuts, cause I'm pretty certain that their early triple- play advertising said this -- though not in so many technical words. > > So of course Vonage and other VoN products will be less rugged. > > > > As I recall, this questionably fair competitive advantage has been > > looked into by ... someone. (Cablecos won't permit competing VoIP > > services to utilize this protected channel, somewhere between > > "generally" and "ever".) > As I said, this second channel doesn't exist in almost all cases (its > not cost effective nor needed in almost all cases). Having said that > over the top VOIP providers do suffer in comparison because they don't > get the benefit of prioritization in the local cable plant. "Cost-effective"? Could you expand on how the provisioning of a second virtual pipe down the hill to a cable box has any incremental costs at all? Cheers, -- jra
